/*
Copyright 2016 The Kubernetes Authors.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

package listers

import (
	"fmt"

	"k8s.io/apimachinery/pkg/api/errors"
	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
	"k8s.io/apimachinery/pkg/labels"
	"k8s.io/client-go/tools/cache"
	"k8s.io/kubernetes/pkg/api"
	"k8s.io/kubernetes/pkg/api/v1"
)

//  TODO: generate these classes and methods for all resources of interest using
// a script.  Can use "go generate" once 1.4 is supported by all users.

// Lister makes an Index have the List method.  The Stores must contain only the expected type
// Example:
// s := cache.NewStore()
// lw := cache.ListWatch{Client: c, FieldSelector: sel, Resource: "pods"}
// r := cache.NewReflector(lw, &api.Pod{}, s).Run()
// l := StoreToPodLister{s}
// l.List()

// StoreToPodLister helps list pods
type StoreToPodLister struct {
	Indexer cache.Indexer
}

func (s *StoreToPodLister) List(selector labels.Selector) (ret []*v1.Pod, err error) {
	err = cache.ListAll(s.Indexer, selector, func(m interface{}) {
		ret = append(ret, m.(*v1.Pod))
	})
	return ret, err
}

func (s *StoreToPodLister) Pods(namespace string) storePodsNamespacer {
	return storePodsNamespacer{Indexer: s.Indexer, namespace: namespace}
}

type storePodsNamespacer struct {
	Indexer   cache.Indexer
	namespace string
}

func (s storePodsNamespacer) List(selector labels.Selector) (ret []*v1.Pod, err error) {
	err = cache.ListAllByNamespace(s.Indexer, s.namespace, selector, func(m interface{}) {
		ret = append(ret, m.(*v1.Pod))
	})
	return ret, err
}

func (s storePodsNamespacer) Get(name string) (*v1.Pod, error) {
	obj, exists, err := s.Indexer.GetByKey(s.namespace + "/" + name)
	if err != nil {
		return nil, err
	}
	if !exists {
		return nil, errors.NewNotFound(api.Resource("pod"), name)
	}
	return obj.(*v1.Pod), nil
}

// StoreToServiceLister helps list services
type StoreToServiceLister struct {
	Indexer cache.Indexer
}

func (s *StoreToServiceLister) List(selector labels.Selector) (ret []*v1.Service, err error) {
	err = cache.ListAll(s.Indexer, selector, func(m interface{}) {
		ret = append(ret, m.(*v1.Service))
	})
	return ret, err
}

func (s *StoreToServiceLister) Services(namespace string) storeServicesNamespacer {
	return storeServicesNamespacer{s.Indexer, namespace}
}

type storeServicesNamespacer struct {
	indexer   cache.Indexer
	namespace string
}

func (s storeServicesNamespacer) List(selector labels.Selector) (ret []*v1.Service, err error) {
	err = cache.ListAllByNamespace(s.indexer, s.namespace, selector, func(m interface{}) {
		ret = append(ret, m.(*v1.Service))
	})
	return ret, err
}

func (s storeServicesNamespacer) Get(name string) (*v1.Service, error) {
	obj, exists, err := s.indexer.GetByKey(s.namespace + "/" + name)
	if err != nil {
		return nil, err
	}
	if !exists {
		return nil, errors.NewNotFound(api.Resource("service"), name)
	}
	return obj.(*v1.Service), nil
}

// TODO: Move this back to scheduler as a helper function that takes a Store,
// rather than a method of StoreToServiceLister.
func (s *StoreToServiceLister) GetPodServices(pod *v1.Pod) (services []*v1.Service, err error) {
	allServices, err := s.Services(pod.Namespace).List(labels.Everything())
	if err != nil {
		return nil, err
	}

	for i := range allServices {
		service := allServices[i]
		if service.Spec.Selector == nil {
			// services with nil selectors match nothing, not everything.
			continue
		}
		selector := labels.Set(service.Spec.Selector).AsSelectorPreValidated()
		if selector.Matches(labels.Set(pod.Labels)) {
			services = append(services, service)
		}
	}

	return services, nil
}

// StoreToReplicationControllerLister helps list rcs
type StoreToReplicationControllerLister struct {
	Indexer cache.Indexer
}

func (s *StoreToReplicationControllerLister) List(selector labels.Selector) (ret []*v1.ReplicationController, err error) {
	err = cache.ListAll(s.Indexer, selector, func(m interface{}) {
		ret = append(ret, m.(*v1.ReplicationController))
	})
	return ret, err
}

func (s *StoreToReplicationControllerLister) ReplicationControllers(namespace string) storeReplicationControllersNamespacer {
	return storeReplicationControllersNamespacer{s.Indexer, namespace}
}

type storeReplicationControllersNamespacer struct {
	indexer   cache.Indexer
	namespace string
}

func (s storeReplicationControllersNamespacer) List(selector labels.Selector) (ret []*v1.ReplicationController, err error) {
	err = cache.ListAllByNamespace(s.indexer, s.namespace, selector, func(m interface{}) {
		ret = append(ret, m.(*v1.ReplicationController))
	})
	return ret, err
}

func (s storeReplicationControllersNamespacer) Get(name string) (*v1.ReplicationController, error) {
	obj, exists, err := s.indexer.GetByKey(s.namespace + "/" + name)
	if err != nil {
		return nil, err
	}
	if !exists {
		return nil, errors.NewNotFound(api.Resource("replicationcontroller"), name)
	}
	return obj.(*v1.ReplicationController), nil
}

// GetPodControllers returns a list of replication controllers managing a pod. Returns an error only if no matching controllers are found.
func (s *StoreToReplicationControllerLister) GetPodControllers(pod *v1.Pod) (controllers []*v1.ReplicationController, err error) {
	if len(pod.Labels) == 0 {
		err = fmt.Errorf("no controllers found for pod %v because it has no labels", pod.Name)
		return
	}

	key := &v1.ReplicationController{ObjectMeta: metav1.ObjectMeta{Namespace: pod.Namespace}}
	items, err := s.Indexer.Index(cache.NamespaceIndex, key)
	if err != nil {
		return
	}

	for _, m := range items {
		rc := m.(*v1.ReplicationController)
		selector := labels.Set(rc.Spec.Selector).AsSelectorPreValidated()

		// If an rc with a nil or empty selector creeps in, it should match nothing, not everything.
		if selector.Empty() || !selector.Matches(labels.Set(pod.Labels)) {
			continue
		}
		controllers = append(controllers, rc)
	}
	if len(controllers) == 0 {
		err = fmt.Errorf("could not find controller for pod %s in namespace %s with labels: %v", pod.Name, pod.Namespace, pod.Labels)
	}
	return
}

// StoreToServiceAccountLister helps list service accounts
type StoreToServiceAccountLister struct {
	Indexer cache.Indexer
}

func (s *StoreToServiceAccountLister) List(selector labels.Selector) (ret []*v1.ServiceAccount, err error) {
	err = cache.ListAll(s.Indexer, selector, func(m interface{}) {
		ret = append(ret, m.(*v1.ServiceAccount))
	})
	return ret, err
}

func (s *StoreToServiceAccountLister) ServiceAccounts(namespace string) storeServiceAccountsNamespacer {
	return storeServiceAccountsNamespacer{s.Indexer, namespace}
}

type storeServiceAccountsNamespacer struct {
	indexer   cache.Indexer
	namespace string
}

func (s storeServiceAccountsNamespacer) List(selector labels.Selector) (ret []*v1.ServiceAccount, err error) {
	err = cache.ListAllByNamespace(s.indexer, s.namespace, selector, func(m interface{}) {
		ret = append(ret, m.(*v1.ServiceAccount))
	})
	return ret, err
}

func (s storeServiceAccountsNamespacer) Get(name string) (*v1.ServiceAccount, error) {
	obj, exists, err := s.indexer.GetByKey(s.namespace + "/" + name)
	if err != nil {
		return nil, err
	}
	if !exists {
		return nil, errors.NewNotFound(api.Resource("serviceaccount"), name)
	}
	return obj.(*v1.ServiceAccount), nil
}

// StoreToLimitRangeLister helps list limit ranges
type StoreToLimitRangeLister struct {
	Indexer cache.Indexer
}

func (s *StoreToLimitRangeLister) List(selector labels.Selector) (ret []*v1.LimitRange, err error) {
	err = cache.ListAll(s.Indexer, selector, func(m interface{}) {
		ret = append(ret, m.(*v1.LimitRange))
	})
	return ret, err
}

// StoreToPersistentVolumeClaimLister helps list pvcs
type StoreToPersistentVolumeClaimLister struct {
	Indexer cache.Indexer
}

// List returns all persistentvolumeclaims that match the specified selector
func (s *StoreToPersistentVolumeClaimLister) List(selector labels.Selector) (ret []*v1.PersistentVolumeClaim, err error) {
	err = cache.ListAll(s.Indexer, selector, func(m interface{}) {
		ret = append(ret, m.(*v1.PersistentVolumeClaim))
	})
	return ret, err
}

func (s *StoreToLimitRangeLister) LimitRanges(namespace string) storeLimitRangesNamespacer {
	return storeLimitRangesNamespacer{s.Indexer, namespace}
}

type storeLimitRangesNamespacer struct {
	indexer   cache.Indexer
	namespace string
}

func (s storeLimitRangesNamespacer) List(selector labels.Selector) (ret []*v1.LimitRange, err error) {
	err = cache.ListAllByNamespace(s.indexer, s.namespace, selector, func(m interface{}) {
		ret = append(ret, m.(*v1.LimitRange))
	})
	return ret, err
}

func (s storeLimitRangesNamespacer) Get(name string) (*v1.LimitRange, error) {
	obj, exists, err := s.indexer.GetByKey(s.namespace + "/" + name)
	if err != nil {
		return nil, err
	}
	if !exists {
		return nil, errors.NewNotFound(api.Resource("limitrange"), name)
	}
	return obj.(*v1.LimitRange), nil
}

// PersistentVolumeClaims returns all claims in a specified namespace.
func (s *StoreToPersistentVolumeClaimLister) PersistentVolumeClaims(namespace string) storePersistentVolumeClaimsNamespacer {
	return storePersistentVolumeClaimsNamespacer{Indexer: s.Indexer, namespace: namespace}
}

type storePersistentVolumeClaimsNamespacer struct {
	Indexer   cache.Indexer
	namespace string
}

func (s storePersistentVolumeClaimsNamespacer) List(selector labels.Selector) (ret []*v1.PersistentVolumeClaim, err error) {
	err = cache.ListAllByNamespace(s.Indexer, s.namespace, selector, func(m interface{}) {
		ret = append(ret, m.(*v1.PersistentVolumeClaim))
	})
	return ret, err
}

func (s storePersistentVolumeClaimsNamespacer) Get(name string) (*v1.PersistentVolumeClaim, error) {
	obj, exists, err := s.Indexer.GetByKey(s.namespace + "/" + name)
	if err != nil {
		return nil, err
	}
	if !exists {
		return nil, errors.NewNotFound(api.Resource("persistentvolumeclaims"), name)
	}
	return obj.(*v1.PersistentVolumeClaim), nil
}

// IndexerToNamespaceLister gives an Indexer List method
type IndexerToNamespaceLister struct {
	cache.Indexer
}

// List returns a list of namespaces
func (i *IndexerToNamespaceLister) List(selector labels.Selector) (ret []*v1.Namespace, err error) {
	err = cache.ListAll(i.Indexer, selector, func(m interface{}) {
		ret = append(ret, m.(*v1.Namespace))
	})
	return ret, err
}

func (i *IndexerToNamespaceLister) Get(name string) (*v1.Namespace, error) {
	obj, exists, err := i.Indexer.GetByKey(name)
	if err != nil {
		return nil, err
	}
	if !exists {
		return nil, errors.NewNotFound(api.Resource("namespace"), name)
	}
	return obj.(*v1.Namespace), nil
}
